In applications where a transistor, such as a power transistor, for example an IGBT (insulated gate bipolar transistor), is used to switch higher powers, pulse currents may be generated during the switching on of the transistor. Those pulse currents may be originating from other circuit components provided upstream of the power transistor which may discharge, e.g. an intermediate voltage circuit or a voltage link circuit arranged between the power supply and the power transistor. Pulse currents may have magnitudes lying outside the specification range of the power transistor and may thereby damage or even destroy the power transistor.
In order to prevent pulse currents from occurring, the power transistor may be switched via a high gate resistance such that the switching process is slowed down. However, the beneficial effect of this measure with regard to reducing the pulse currents is very small and can be neglected. A further possible countermeasure may be seen in providing a capacitance which is coupled in parallel between the gate and emitter/source of the power transistor. Unfortunately, this measure may drastically increase switch-off losses since the power transistor is switched off slowly and therefore a tail current may present, contributing to total switching losses.